The present invention relates to a circuit for protecting electrically operated lighting elements, especially LEDs, for signaling or illumination purposes.
Electrically operated lighting elements, especially in the form of LEDs, are often used in the automobile industry, preferably in the tail light fixture. The LEDs are sensitive semi-conductor lighting elements that can be easily damaged when positive or negative voltage peaks occur. Such voltage peaks may, for example, result when connecting the supply voltage or when the load of an inductive consumer element is shut down. The use of diodes having resistors serially connected downstream thereof for limiting current for suppressing high voltage negative impulses is known. However, such switching devices, in general, do not allow to control the lighting elements. Instead, the current supply depends on the supply voltage. Furthermore, such switching devices are not protected against positive voltage.
It is therefore an object of the present invention to embody the aforementioned circuit such that they are protected against positive over voltages and limit the current supply to the lighting element to a level that prevents damage.